[RFC PATCH v3 5/9] libcamera: process: Ensure that file descriptors are nonnegative

[Kieran Bingham]

Quoting Barnabás Pőcze (2025-03-25 18:08:17)
> Return `-EINVAL` from `Process::start()` if any of the file
> descriptors are negative as those most likely signal some
> kind of issue such as missed error checking.
> 
> Signed-off-by: Barnabás Pőcze <barnabas.pocze at ideasonboard.com>

Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

> ---
>  src/libcamera/process.cpp | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/src/libcamera/process.cpp b/src/libcamera/process.cpp
> index 716523acc..62e63255b 100644
> --- a/src/libcamera/process.cpp
> +++ b/src/libcamera/process.cpp
> @@ -243,6 +243,11 @@ int Process::start(const std::string &path,
>         if (pid_ > 0)
>                 return -EBUSY;
>  
> +       for (int fd : fds) {
> +               if (fd < 0)
> +                       return -EINVAL;
> +       }
> +
>         int childPid = fork();
>         if (childPid == -1) {
>                 ret = -errno;
> @@ -282,6 +287,8 @@ void Process::closeAllFdsExcept(const std::vector<int> &fds)
>         std::vector<int> v(fds);
>         sort(v.begin(), v.end());
>  
> +       ASSERT(v.empty() || v.front() >= 0);
> +
>         DIR *dir = opendir("/proc/self/fd");
>         if (!dir)
>                 return;
> -- 
> 2.49.0
>